CAMP PENDLETON -- The Pentagon released the names Tuesday of four Camp Pendleton-based Marines killed in a military helicopter collision over southern Afghanistan.

A UH-1N Huey with Cpl. Gregory M.W. Fleury, 23, and Capt. Eric Jones, 29, aboard crashed into an AH-1 Cobra carrying Capt. David Mitchell, 30, and Capt. Kyle Van De Giesen, 29, in Helmand Province early Monday morning, said Sgt. Sean McGinty, a spokesman for the 3rd Marine Aircraft Wing.

Fleury, Jones and Van De Giesen were assigned to Marine Light Attack Helicopter Squadron 169, Marine Aircraft Group 39, 3rd MAW, I Marine Expeditionary Force.

Mitchell was assigned to Marine Light Attack Helicopter Squadron 367, Marine Aircraft Group 39, 3rd MAW, I Marine Expeditionary Force.

Fleury hailed from Anchorage, Alaska; Jones from Westchester, N.Y.; Mitchell from Loveland, Ohio; and Van De Giesen from North Attleboro, Mass.

In a separate air crash in Afghanistan on Monday, seven American soldiers and three U.S. civilians died when the helicopter they were in went down in western Afghanistan, officials said.

The combined 14 deaths from the loss of the three aircraft made it the deadliest day for U.S. personnel in the Islamic republic since 2005.